Report of the second round table discussion on the development of genetically improved strain of Macrobrachium

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Report of the second round table discussion on the development of genetically improved strain of Macrobrachium

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Report of the Second Round Table Discussion on the Development of Genetically Improved Strain of Macrobrachium : a collaborative research under the Aquaculture Component of the ASEAN-SEAFDEC Special Five-Year Program on Sustainable Fisheries for Food Security in the ASEAN Region, Dagupan City and Science City of Muñoz, Philippines 16-21 September 2004.

The Second Round Table Discussion on the Development of Genetically Improved Strain of Macrobrachium was held in the Philippines in September 2004 to evaluate the progress of activities of the collaborative research and as a follow-up to the First Round Table Discussion, which was convened in Indonesia in 2003. During the said Round Table Discussion, delineation of responsibilities was agreed upon by the participating countries – Indonesia, the Philippines and Thailand. One of the recommendations during the First Round Table Discussion was to conduct a yearly evaluation of the project activities to enable the experts to get to know of each other’s activities and come up with a consistent and improved technology on production of good quality freshwater prawn seeds that can be made available for rural aquaculture in the region.

This publication contains the progress of the collaborative research presented during the Second Round Table Discussion.

Although the giant freshwater prawn (Macrobrachium rosenbergii) has been domesticated in Thailand for over decades, appropriate selective breeding program has yet to be achieved. Good quality seeds for the Machrobrachium aquaculture industry is therefore not regularly produced. One of the selective breeding programs on improving growth performance of the domesticated strain have been carried out at the Aquatic Animal Genetics Research and Development Institute (AAGRDI), Department of Fisheries of Thailand. AAGRDI has now developed improved and domesticated stock of Macrobrachium rosenbergii for two generations. Meanwhile, domesticated stocks from private hatcheries have also been acquired.

There is, therefore, the need to develop another improved stock of this species basically from these two domesticated stocks together with a wild stock in order to improve the genetic diversity of the base population for further selective breeding program. Macrobrachium wild stock has been domesticated under hatchery conditions at the AAGRDI for one generation. Generally, a good base population for genetic improvement program requires high genetic variation as well as an ideally suitable stock that can be well adapted for each of different local environments. Therefore, all proper crosses of these three stocks need to be cultured in different areas of the country and then evaluated on both performance and genetic variation before selective breeding program takes place.

Research and commercial production of the freshwater prawn, Macrobrachium sp., in the Philippines are yet not well-developed. Although studies on Macrobrachium sp. (or ulang as it is locally known), started at the Binangonan Freshwater Station (BFS) of SEAFDEC/AQD in the mid-1980s, research efforts were discontinued soon thereafter because of: (a) inadequate technical skills; (b) problems with larval rearing and the domestication of wild stocks; and (c) the Macrobrachium sp. is being considered in the Philippines as a low priority species in contrast to commercially important freshwater commodities like tilapia and milkfish.

That was two decades ago and in retrospect, researches continued and the freshwater prawn in the Philippines could have been successfully domesticated and current problems concerning the limited aquaculture production of genetically depauperate non-indigenous stocks could have been resolved. With the renewed interest in the culture of alternative species like the freshwater prawn, researchers at the Binangonan Freshwater Station (BFS) started to conduct some studies on the refinement of breeding, larval rearing and culture of Macrobrachium rosenbergii since 2003.

There is an expanding interest in the culture of freshwater prawn in the Philippines. This is attributed to the extensive campaign of the government, the Bureau of Fisheries and Aquatic Resources (BFAR) and some private entrepreneurs to disseminate information and seeds of the prawn nationwide.

Although freshwater aquaculture in the Philippines is still dominated by tilapia, which is an exotic fish, the profit from tilapia culture is not well appreciated except for family consumption or nutrition purposes. The freshwater prawn, an indigenous species, remains to be an important species. With freshwater prawn as an alternative species, farmers can diversify and derive higher profit from their ponds. In the Philippines, Macrobrachium rosenbergii stocked in 2,000 m2 ponds may grow to about 45 g after four months and 90 to 100 g in seven months of culture (Rosario, 2002). The price of the species is five times higher than tilapia.

During the first Round Table Discussion on the Development of Genetically Improved Strain of Macrobrachium held at the Freshwater Aquaculture Development Center, Sukabumi, West Java, Indonesia in November 2003, the delegates from Thailand reported that the Philippine wild stocks of Macrobrachium, M. rosenbergii rosenbergii Philippine strain could be a better variety and therefore must be protected from contamination by non-indigenous strains. The report supports and confirms the importance of the activity of the National Integrated Fisheries and Development Center (NIFTDC) to collect live specimens of various strains of Macrobrachium in the country and review their performance in terms of growth and fecundity.

The giant freshwater prawn (Macrobrachium rosenbengii) is one of the indigenous prawns found in many parts of the country. Locally known as ulang, it is a hardy species that is easily farmed. On the average, farmed ulang weighs from 30 to 100 grams, which translates to 10 to 25 pieces per kilo. This is very much comparable to the medium to large or jumbo sizes of brackishwater tiger shrimps or sugpo. In the wild, ulang grow as much as 500 g and sells at 300 to 350 pesos/kg ($1=P55.50), however, the quantity harvested is limited and is dependent on its seasonality.

Despite the development of both hatchery and grow-out technologies for ulang, there is really no significant commercial production in the country yet, except in BFAR-operated hatcheries in Muñoz and in Dagupan. To date, the only private ulang hatchery is MBL Farms producing up to 150,000 PL or post-larvae per run (45 days), although there are entrepreneurs trained in Muñoz who are also operating small backyard hatcheries for prawns.

With the emerging global market on this giant freshwater prawn coupled with improved technologies, it is but imperative to speed up the development of the industry in the country. However, the industry is faced with problems and constraints that include:

• insufficient breeders

• insufficient supply of post-larvae or PL for stocking

• limited market supply

• limited funds for interested stakeholders

• insufficient information

• inadequate promotion of technology transfer

• very few skilled and/or trained technicians

• research and development of ulang hatchery and grow-out are still wanting new technologies

One way of increasing the production of freshwater prawn is through a genetic improvement program. The GI Macro seeds (Genetically Improved Macrobrachium rosenbergii) that Indonesia developed have been released to farmers since 2001. However, producing 50 g prawns have become difficult with survival rate of as low as 40% after 9-11 months of culture. Thus, the program to improve growth rate and increase the edible portion of the prawn was conducted.

Giant freshwater prawn is an important commodity that is successfully cultured in Indonesia. Its culture has been developed in several areas of West Java, i.e., Ciamis (Tambaksari, Pamarican and Kalipucang) and Tasikmalaya. The Indonesian Government has developed a hatchery in Jogjakarta province (Central Java), while the private sector control about seven hatcheries. In East Java, freshwater prawn is cultured in brackishwater ponds. Freshwater prawn culture has also spread to some areas of Bali Island, e.g., in Gianyar, Klungkung, Buleleng and Tabanan.

Indonesia has been recognized as the center of origin of the giant freshwater prawn because about 19 identified species are found in almost all islands of the country (Holthuis, 1980). However, this genetic resource is not yet fully used in freshwater prawn culture. Although freshwater prawn culture has been widely developed in Indonesia, some problems have been encountered, e.g., declining growth rate, disease, and the small edible portion (abdominal muscle).

In recent years, the Government of Indonesia has stressed the need to increase the production of freshwater prawn. One way to increase production is through the genetic improvement program. In 2001, the GI Macro (Genetically Improved Macrobrachium rosenbergii), strain of freshwater prawn has been developed and released to farmers.